A shock absorber spring is provided. The shock absorber spring is especially suitable for hanging and controlling the movement of heavy oscillating articles, such as the tub of a washing machine. The shock absorber spring is constructed as a single unit having an internal shaft, with a built in compression limiter which passes back through the coils of the spring. A first end of the internal shaft is secured or hung to a stationary object (such as the top of a washing machine) while the second end of the internal shaft is surrounded by the spring and hangs down in a generally vertical orientation. The second end of the shock absorber spring is then secured or hung directly to the heavy, moving object and allows the heavy, moving object to move in a restricted, desired manner by dampening and absorbing the vibrations of the object. The shock absorber spring has an internal travel limiter which may make contact with an extended bump located at the bottom of the internal shaft wherein the internal travel limiter contacts the extended bump and prevents the shock absorber spring from over compressing.
Springs used in shock absorbers for washing machines are well known. For example, U.S. Pat. No. 4,343,452 to Bauer discloses an elastic support for a horizontally rotating washing machine or the like in which two spring support strut assemblies are disposed substantially in the middle of the machine and to either side of a vertical plane which includes the axis of rotation. Each of the spring strut assemblies is double-acting, i.e., it has an upper guide rod and a lower guide rod, each of which is surrounded by a compression spring. The top of the upper guide rod is attached to the washing machine housing and the bottom of the lower guide rod is attached to the base of the machine. The free ends of the guide rods move axially within a single guiding and damping casing which has internal passages for guiding the rods. The casing may consist of two or more parts and is so constructed that when the casing parts are clamped together with a variable force, the casing is deformed and a varying amount of radial pressure is applied by the walls of the passages to the surface of the guide rods, thereby causing a selectable amount of damping friction with respect to the axial motion of said guide rods.
Further, U.S. Pat. No. 5,606,879 to Froelicher discloses an automatic washing machine suspension system having a plurality of suspension units. Each unit includes a rod suspended from a stationary support ring. A hollow cylinder, with a cylindrical side wall and a transverse base, is connected to the moving system and is mounted around the distal end of the rod. A piston mounted on the rod within the cylinder side wall includes a circumferentially continuous skirt extending axially of the side wall. A retainer spring mounted on the rod within the skirt includes a series cantilever beam fingers biasing the piston skirt into engagement with the cylinder side wall. A washer is mounted on the rod within the fingers. A coil spring is mounted around the rod and extends between the base of the cylinder and the piston.
Still Further, U.S. Pat. No. 5,520,029 to Savkar discloses a suspension spring assembly for a washing machine having a coil spring in compression. The suspension spring system uses a snubber mounted inside the coil spring to help dampen and isolate unbalanced load excursions by using the positive displacement pumping action of air being forced through an orifice in the snubber. A second snubber may be employed with the coil spring.
However, these patents fail to describe a shock absorber spring which is easy to use and efficient as in the present device. Further, these patents fail to provide a shock absorber spring which allows a user to utilize a single unit shock absorber spring as described in the present application while increasing tensile strength and reducing weight.